Subcutaneous fibrosarcomas with pulmonary metastases in a white tiger (Panthera tigris) and a lion (Panthera leo)

Two cases of recurrent subcutaneous fibrosarcomas in a white tiger and a lion were observed and the animals were euthanised humanely due to clinical deterioration. in both animals, postmortem examination revealed multinodular, white to fawn, firm to greasy, subcutaneous masses at the left side of the thorax infiltrating into the adjacent musculature. Furthermore, the tiger showed a single mass and the lion multiple masses in the lung. Histopathologically, the subcutaneous and pulmonary masses consisted of spindle-shaped neoplastic cells with necrotic areas, and infiltration with multinucleated giant cells and lymphocytes. immunohistochemically, tumour cells labelled positive for vimentin and negative for desmin, factor Viii-related antigen, smooth muscle actin S100, CD31 and nerve growth factor receptor p75. Thus, the pulmonary tumours were diagnosed as metastases of subcutaneous fibrosarcomas. like domestic cats, also large, non-domestic felids could be predisposed for metastasising fibrosarcoma, which may be associated with injections or trauma.